When war threatened to break out between the Tau and Imperial forces on the planet, both made the independent decision to send a scouting party into the tunnels under the capital city, to locate the third party stirring up trouble. Cain's party, led by InquisitorAmberley Vail, bumped into the Tau expedition, which included Gorok. Their previous acquaintance helped to broker a temporary truce with the Imperials (though not, unfortunately, before one of the Kroot was killed by an Imperial sniper; Gorok appeared to take this phlegmatically, complimenting the Valhallan sniper on his skill). Because of the Kroot's ability to "taste" genetic variation, Gorok's observations alerted Vail and Cain to the true nature of their opponents - a Genestealer cult.[1b]

When it became apparent to Gorok that the Genestealer Hybrids had discovered the head of the slain Kroot, he acted to destroy the remains rather than let the Kroot's genetics fall into the Genestealers' hands. However, as soon as he opened fire, the party was discovered. As they retreated, Cain last saw Gorok being torn apart by a Purestrain Genestealer.[1c]